As used herein, the term “decontamination” refers to processes, including, but not limited to, “deactivation of biocontamination,” “deactivation of chemical contamination,” “sterilization,” “disinfection” and “sanitization.”
Detergents are widely used in a variety of decontamination processes, including, but not limited, to healthcare decontamination processes, pharmaceutical manufacturing processes, as well as household/domestic washing (such as clothes washing and dish washing). The detergents are typically comprised of one or more active detergent chemical components that are combined with water to form a detergent solution. As used herein, the term “detergent” refers to the one or more detergent chemical components.
Detergent used in healthcare decontamination processes includes, but is not limited to, enzymatic, alkaline, acidic and neutral detergent (e.g., liquid detergents, such as Renu-Klenz, Liqui-Jet 2, Klenzyme, Enzycare 2, NpH-Klenz, Instru-Klenz, and Criti-Klenz, sold by STERIS Corporation). Detergent used in pharmaceutical manufacturing processes includes, but is not limited to, alkaline, acidic, oxidative (e.g., bleach) and neutral detergent (e.g., liquid detergents such as CIP 100, CIP 200, CIP 220, CIP 300, CIP 150, sold by STERIS Corporation). The detergent may be primarily inorganic-based or organic-based.
The active ingredients for some of the abovementioned detergents are identified in the table set forth below:
DetergentActive IngredientsRenu-KlenzBlend of nonioinic surfactantsNeutral pHLiqui-Jet 2Anionic SurfactantEthylenediaminetetraacetic acidPotassium and Sodium HydroxideSilicatesKlenzymeProtease EnzymeAnionic SurfactantBuffersEnzycare 2Protease EnzymesAnionic SurfactantBuffersNpH-KlenzBlend of nonionic surfactantsNeutral pHInstru-KlenzEthylenediaminetetraacetic acidAmphoteric SurfactantCriti-KlenzEthylenediaminetetraacetic acidAmphoteric SurfactantCIP 100Potassium HydroxideAmphoteric SurfactantEthylenediaminetetraacetic acidCIP 200Phosphoric AcidAmphoteric SurfactantCIP 220Glycolic AcidAmphoteric SurfactantCIP 300Amphoteric SurfactantNonioinic SurfactantNeutral pHCIP 150Anionic SurfactantSodium HypochloriteSilicatesPotassium Hydroxide
In the healthcare industry, medical instruments and other articles may be cleaned manually, or by use of an automated washer apparatus (e.g., Amsco Reliance 444 washer from STERIS Corporation). In an automated washer apparatus a detergent, in liquid or powdered/granular form, is typically dispensed from a dispenser container (e.g., a detergent cup) as water is circulated therethrough to form a detergent solution. A peristaltic pump may be used to introduce a calibrated quantity of detergent solution into a washing chamber. However, there is no convenient or efficient manner to confirm that the detergent solution includes a proper detergent concentration. In this regard, a sample of the detergent solution is taken, and titration is performed to determine the detergent concentration therein. Since the detergent concentration is not determined continuously during a washing process, the automated washer apparatus will continue a washing process without alerting an operator of an improper detergent concentration. Typically, manual observation of detergent inside a detergent dispensing container is used to determine whether the detergent dispensing container needs to be replaced in order to provide a proper concentration of detergent in the detergent solution.
Titration of a detergent solution is time consuming, and is difficult and inconvenient to perform on a regular automated basis. Furthermore, the calibration of the peristaltic pump can change, as tubing becomes worn, the pump loses efficiency and/or the type of detergent is changed. The lack of a proper detergent concentration in the detergent solution can result in improperly cleaned medical instruments, increased reprocessing costs, and risks to patient safety. Furthermore, prior art processes for determining detergent concentration do not allow for fully automated procedures that can reduce human error.
In the pharmaceutical industry, two types of cleaning processes are commonly used to clean manufacturing equipment, namely, “clean in place” (CIP) and “clean out of place” (COP). A CIP process typically occurs by flowing or flooding equipment (e.g., process vessels, piping and ancillary equipment) with a detergent solution. CIP and COP processes can be automated or manual. However, a CIP process is usually an automated process, since it is typically used to clean large equipment that is difficult or awkward to clean manually. A COP process is ordinarily a manual cleaning process, since it is typically used to clean smaller or disassembled equipment. CIP and COP processes are both required to be “validated” processes. Accordingly, the CIP and COP processes must be well defined and tested, and must be conducted in a consistent manner each and every time. Accordingly, a measurement of the detergent concentration in the detergent solution must be made to verify that the proper detergent concentration is used. As discussed above, a sample of detergent solution can be taken and analyzed in a laboratory using standard techniques, such as titration. If the concentration of detergent in the detergent solution is determined to be improper, appropriate corrective action can be taken.
The foregoing analysis of detergent concentration is time consuming and is not done in real time. The time required for the off-line analyses can result in wasted resources and production delays. Furthermore, the process for determining detergent concentration does not allow for fully automated procedures that can reduce or eliminate human error.
The present invention provides a method and apparatus for monitoring the concentration of detergent used in a decontamination process, and addresses the aforementioned problems, as well as others.